Coal Specifications--Impact on Power Station Performance
AUTHOR: Nina M. Skorupska
DATE: January 1993
This report examines the impacts of coal properties on power stations burning pulverised fuels The properties used for defining specifications for coal selection are reviewed, together with their influence on power station performance. The main power station components are considered in relation to those coal properties which affect their performance. There is a review of tools, including computer models, for coal selection and prediction of station performance. Coal properties of greatest concern to operators include ash, sulphur, moisture and volatile matter, heating value and grindability.
Operators continue to use tests for coal assessment and selection that were mostly developed for coal uses other than combustion. Because these do not relate well to actual practice there is still a need for expensive large scale test burns to confirm suitability. With advances in computer technology some utilities are adopting expert unit or integrated models to plan and operate generating units. Others are sceptical of the ability to devise a truly representative model of a coal combustion plant using data from current tests.
The report identifies the need to develop internationally acceptable methods of defining coal characteristics so that combustion plant performance can be predicted more effectively. There is also a need to establish economic parameters which can predict the effects of coals on plant performance and hence on the cost of electricity.